A335327 Numbers k such that iphi(k) divides k, where iphi is an infinitary analog of Euler's phi function (A091732).

1, 2, 6, 12, 24, 72, 120, 240, 480, 1440, 2880, 5760, 8640, 17280, 65280, 86400, 120960, 130560, 259200, 391680, 783360, 1566720, 2350080, 4700160, 23500800, 32901120, 47001600, 70502400, 94003200, 470016000, 1410048000, 2820096000, 4294901760, 5640192000, 8460288000

Offset: 1

Author

Amiram Eldar, Jun 01 2020

Keywords

• nonn

Examples

			6 is a term since iphi(6) = 2 is a divisor of 6.
		

Crossrefs

Cf. A007694, A091732, A319481.

Programs

Mathematica

f[p_, e_] := p^(2^(-1 + Position[Reverse @ IntegerDigits[e, 2], 1])); a[1] = 1; iphi[n_] := Times @@ (Flatten@(f @@@ FactorInteger[n]) - 1);  Select[Range[10^5], Divisible[#,a[#]] &]